New York Gov. Andrew Cuomo’s new college-affordability plan got a boost from Hillary Clinton Wednesday, who appeared with Mr. Cuomo as he signed it into law.

Mrs. Clinton praised the plan in remarks as a model for the country. “It’s going to send a message of hope to countless families,” she said at a City University of New York campus in Queens, “and to employers, that they want to start making plans to come to New York.”